D. A. Smagin

Bio: D. A. Smagin is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Social defeat & Ventral tegmental area. The author has an hindex of 11, co-authored 40 publications receiving 328 citations.

Repeated positive fighting experience in male inbred mice

Abstract: Repeated aggression is a frequent symptom of many psychiatric and neurological disorders, including obsessive-compulsive and attention deficit hyperactivity disorders, bipolar and post-traumatic stress disorders, epilepsy, autism, schizophrenia and drug abuse. However, repeated aggression is insufficiently studied because there is a lack of adequate models in animals. The sensory contact model (SCM), widely used to study the effects of chronic social defeat stress, can also be used to investigate the effects of repeated aggression. Mice with repeated positive fighting experience in daily agonistic interactions in this model develop pronounced aggressiveness, anxiety and impulsivity, disturbances in motivated and cognitive behaviors, and impairments of sociability; they also demonstrate hyperactivity, attention-deficit behavior, motor dysfunctions and repetitive stereotyped behaviors, such as jerks, rotations and head twitches. In this protocol, we describe how to apply the SCM to study repeated aggression in mice. Severe neuropathology develops in male mice after 20-21 d of agonistic interactions.

Dysfunction in Ribosomal Gene Expression in the Hypothalamus and Hippocampus following Chronic Social Defeat Stress in Male Mice as Revealed by RNA-Seq.

Abstract: Chronic social defeat stress leads to the development of anxiety- and depression-like states in male mice and is accompanied by numerous molecular changes in brain. The influence of 21-day period of social stress on ribosomal gene expression in five brain regions was studied using the RNA-Seq database. Most Rps, Rpl, Mprs, and Mprl genes were upregulated in the hypothalamus and downregulated in the hippocampus, which may indicate ribosomal dysfunction following chronic social defeat stress. There were no differentially expressed ribosomal genes in the ventral tegmental area, midbrain raphe nuclei, or striatum. This approach may be used to identify a pharmacological treatment of ribosome biogenesis abnormalities in the brain of patients with “ribosomopathies.”

Altered Slc25 family gene expression as markers of mitochondrial dysfunction in brain regions under experimental mixed anxiety/depression-like disorder.

Abstract: Development of anxiety- and depression-like states under chronic social defeat stress in mice has been shown by many experimental studies. In this article, the differentially expressed Slc25* family genes encoding mitochondrial carrier proteins were analyzed in the brain of depressive (defeated) mice versus aggressive mice winning in everyday social confrontations. The collected samples of brain regions were sequenced at JSC Genoanalytica ( http://genoanalytica.ru/ , Moscow, Russia). Changes in the expression of the 20 Slc25* genes in the male mice were brain region- and social experience (positive or negative)-specific. In particular, most Slc25* genes were up-regulated in the hypothalamus of defeated and aggressive mice and in the hippocampus of defeated mice. In the striatum of defeated mice and in the ventral tegmental area of aggressive mice expression of mitochondrial transporter genes changed specifically. Significant correlations between expression of most Slc25* genes and mitochondrial Mrps and Mrpl genes were found in the brain regions. Altered expression of the Slc25* genes may serve as a marker of mitochondrial dysfunction in brain, which accompanies the development of many neurological and psychoemotional disorders.

[Serotonergic genes in the development of anxiety/depression-like state and pathology of aggressive behavior in male mice: RNA-seq data].

Abstract: In course of daily agonistic interactions, mice tend to stratify into those with chronic social defeats and those that repeatedly display aggression, which lead to the development of mixed anxiety/depression-like state and the pathology of aggressive behavior, respectively. Using the data of whole transcriptome analysis (RNA-seq), the changes in the expression of serotonergic genes involved in the synthesis, inactivation, and reception of serotonin, as well as of the Creb1 (transcription factor) gene and the Bdnf (brain-derived neurotrophic factor) gene were detected in the striatum (STR), ventral tegmental area (VTA), midbrain raphe nuclei (MRN), hypothalamus (HYP), and hippocampus (HIP) of defeated and aggressive male mice. In mice of both groups, the Tph2, Ddc, Slc6a4, Htr2a, Htr3a, Htr5b, Slc18a2, and Bdnf genes were downregulated in the MRN and the Tph2, Ddc, and Slc6a4 genes were upregulated in the VTA. These changes were more significant in defeated mice. The Htr5b gene has first been shown to be involved in mechanisms of depression and pathology of aggressive behavior. In the defeated mice, the expression levels of the Htr4 and Aldh1b1 genes were increased in the MRN, and expression levels of the Maob, Htr4, Htr1a, and Slc18a2 genes were increased in the VTA, while the expression level of the Htr3a gene was decreased. In the HYP of aggressive mice the Maoa, Htr2a, Htr2c, and Creb1 genes were downregulated and the Htr6 gene was upregulated. In the defeated mice, the Maoa and Creb1 genes were downregulated and the Htr6 and Aldh1b1 genes were upregulated in the HYP. In the STR, the Htr1a gene was downregulated and the Htr7 and Bdnf genes were upregulated. The Htr1b gene was upregulated in the HIP. The coexpression of dopaminergic and serotonergic genes in the MRN and VTA in the control of pathological behaviors is discussed. Thus, the complex pattern of differential expression of serotonergic genes in brain regions developing under repeated agonistic interactions in mice in dependence on behavioral pathology have been observed.

Interaction of Depression and Anxiety in the Development of Mixed Anxiety/Depression Disorder. Experimental Studies of the Mechanisms of Comorbidity (review)

Abstract: The symptoms of depression and anxiety often accompany each other. This is apparent both in clinical practice and in laboratory studies. The combination of anxiety and depression in humans responds more slowly to treatment, requires higher doses of drugs, and increases the probability of suicide and the frequency of recurrences. In addition, existing antidepressants and anxiolytics exert their therapeutic effects even in the monopolar development of anxiety or depression in only a limited number of cases. This review of the literature and our own data analyzes the relationship between anxiety and depression. Psychotropic drugs with different spectra of action in a model of mixed anxiety/depression disorder induced by chronic social stress in male mice showed that the states of anxiety and depression change independently in response to anxiolytics and antidepressants.

Anxiety in high functioning children with autism

Abstract: High-functioning children with autism were compared with two control groups on measures of anxiety and social worries. Comparison control groups consisted of children with specific language impairment (SLI) and normally developing children. Each group consisted of 15 children between the ages of 8 and 12 years and were matched for age and gender. Children with autism were found to be most anxious on both measures. High anxiety subscale scores for the autism group were separation anxiety and obsessive-compulsive disorder. These findings are discussed within the context of theories of autism and anxiety in the general population of children. Suggestions for future research are made.

Identification of genes

Abstract: A method of identifying microorganisms with reduced adaptability to a particular environment, wherein (1) each microorganism is independent by insertional inactivation of a gene with a nucleic acid comprising a unique marker sequence. Mutating to provide a plurality of microorganisms, or clones of said microorganisms, such that each mutation has a different label sequence; (2) providing storage samples of each mutation produced by step (1), respectively, and providing storage nucleic acids each comprising a unique label sequence from each mutation; (3) introducing a plurality of mutations produced by step (1) into the specific environment such that the microorganisms capable of growing in the specific environment grow in the above environment; (4) recovering the microorganisms or selected portions thereof from the environment and separating nucleic acids from the recovered microorganisms; (5) comparing all label sequences in the nucleic acid isolated in step (4) with the unique label sequences of each of the stored mutations as in step (2); and (6) any label isolated in step (4). Screening for individual mutations that also do not have a sequence.

Animal models of major depression and their clinical implications.

Abstract: Major depressive disorder is a common, complex, and potentially life-threatening mental disorder that imposes a severe social and economic burden worldwide. Over the years, numerous animal models have been established to elucidate pathophysiology that underlies depression and to test novel antidepressant treatment strategies. Despite these substantial efforts, the animal models available currently are of limited utility for these purposes, probably because none of the models mimics this complex disorder fully. It is presumable that psychiatric illnesses, such as affective disorders, are related to the complexity of the human brain. Here, we summarize the animal models that are used most commonly for depression, and discuss their advantages and limitations. We discuss genetic models, including the recently developed optogenetic tools and the stress models, such as the social stress, chronic mild stress, learned helplessness, and early-life stress paradigms. Moreover, we summarize briefly the olfactory bulbectomy model, as well as models that are based on pharmacological manipulations and disruption of the circadian rhythm. Finally, we highlight common misinterpretations and often-neglected important issues in this field.

Федеральное государственное бюджетное учреждение «Научно-исследовательский институт комплексных проблем сердечно-сосудистых заболеваний» Сибирского отделения Российской академии медицинских наук, Кемерово, Россия

Abstract: Натрийуретические пептиды (НУП) являются важными биомаркерами в диагностике и определении прогноза у пациентов с сердечной недостаточностью (СН). Оценка динамики концентрации НУП (BNP, Nt -proBNP) может быть использована в качестве критерия успешности проводимой терапии. так, при достижении целевых уровней НУП можно прогнозировать благоприятный исход заболевания. В настоящее время лечение СН с учетом уровней НУП является частью рекомендаций по лечению СН (класс IIа) и улучшению ее исхода (класс IIб) в США, однако такой подход не используется в российских клиниках. Цель. Представить современный взгляд на возможность использования НУП для оценки эффективности проводимой терапии пациентов с СН. Ключевые слова: натрийуретические пептиды, сердечная недостаточность, оценка эффективности терапии.